German submarine U-765 was a German Type VIIC U-boat created for service in World War II. U-765 was notable for not suffering any casualties until the time of her sinking. The U-boat did not sink or damage any ships.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-765 had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two Garbe, Lahmeyer & Co. RP 137/c double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-765 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
U-765 was sunk on 6 May 1944 in the North Atlantic, in position , by depth charges from two Swordfish aircraft of 825 Naval Air Squadron from the British Escort Carrier , operating alongside the British frigates , and . The attack left 37 dead and 11 survivors.